Tony Blair was facing a public grilling today over whether he had backed off on plans for controversial university top-up fees.

The Prime Minister reportedly decided to delay a vote until the New Year, after being warned Labour rebels could defeat him.

Downing Street last night rejected suggestions that the Commons showdown had been delayed, saying: "We have not got a date." But Mr Blair was set to be pressed on the issue at his monthly media briefing.

A motion condemning the plans to introduce £3,000-a-year tuition fees has been signed by 140 rebel Labour MPs.

Education Secretary Charles Clarke urged the PM to press ahead with the vote, according to reports. However, whips are said to have warned him only around 40 of the rebels could be won over. At least 50 are needed.

Now Mr Blair faces the threat of an even greater revolt than he did over foundation hospitals, where his 161 majority was slashed to just 17. The vote brought claims that the PM was losing his grip and both issues looked certain to be raised today.